A light emitting diode (hereinafter, referred to as an LED) has various colors in a form of a point source of light to be initially used as a simple display device but has been gradually used in various fields such as a monitor of a laptop/desktop computer and an area display device, or the like, due to advantages such as light optical efficiency, long lifespan, or the like. Particularly, recently, a usage range of the LED has been gradually enlarged up to fields of illumination and a liquid crystal display (LCD) television (TV) backlight.
In the case of the LCD TV backlight and LED illumination, a plurality of light emitting devices configures an array on a board to be used due to high brightness per unit area and flat luminescence. In this array configuration, it is significantly important factor in maintaining a lifespan and quality of the LED to effectively radiate heat generated from LED.
As the LED array board, for smooth heat-radiation, a metal core printed circuit board (MCPCB) is used instead of a copper clad lamination (CCL) used in a PCB according to the related art. Generally, this MCPCB has a three layer structure configured of a metal base layer, a dielectric layer, and a copper foil.
The dielectric layer may be made of an epoxy resin filled with heat conductive particles in order to increase heat conductivity. An electrode circuit may be manufactured by forming a resist pattern and etching the board using a lithography technology similarly to the PCB according to the related art. However, the etching process for forming the electrode circuit is significantly complicated, and a large amount of waste etchant may be generated during the process. In addition, in the LED board based on the MCPCB, heat radiation performance may be significantly limited due to the epoxy dielectric layer.
A technology of forming an electrode circuit by etching using an MCPCB, forming an opening part from a portion on which an LED is mounted to an insulating layer, attaching heat-sink slug thereto, and mounting other LED members thereon has been disclosed in Korean Utility Model No. 20-0404237. However, it may be difficult to clearly detach the attached insulating layer, this technology runs counter to the trend of the assembly scheme as described above, and economic feasibility thereof is low.
An LED array board in which only LED chips are extracted and mounted on a separate board configured of a depressed-mounting part, an insulating layer, a bonding die, a reflector, and an electrode, without using a packaged LED, has been disclosed in Korean Patent No. 696063 (Patent Document 1). However, this board may not have a united standard in terms of the characteristics of the board, complicate processes such as a machining process, various layers forming processes, a pattern forming process, a directly molding process on the board, should be performed. In addition, this board runs counter to the trend of the assembly scheme, and economic feasibility thereof is low.